27.6.1: Flexural deformities in foals

Question 1

Condition? Treatment?

Answer 1

Congenital hyperextension (laxity)
* Common
* Toe is elevated and palmar/ plantar fetlock is sunken

Treatment
* Usually self-corrects within a few weeks; confine to small grass pen
* Skin abrasions may occur on palmar/ plantar fetlock -> protect with bandages
* Glue on heel extension shoes may be required

Question 2

Condition? Treatment?

Answer 2

Congenital hyperflexion (contracture)
* May cause dystocia, may prevent foal standing
* Can treat medically or surguically

Medical treatment
* Light exercise - may spontaneously resolve
* 3g oxytetracycline in 500ml saline slow IV within a few days of birth -> inhibits tractional structuring of collagen fibrils. Tendons and ligaments more susceptible to elongation during normal weight bearing hence exercise.
* Toe extensions and heel reduction
* NSAIDs and omeprazole
* Splints or casts -> encourages relaxation of musculotendinous unit

Surgery rarely required and only undertaken when medical treatment fails.

Question 3

Acquired hyperflexion

Answer 3

• Pain causes flexion withdrawal reflex and subsequent muscle contraction
• Either there is rapid bone growth and tendons unable to keep up -> functional shortening of tendons where resulting tension is painful
• OR there is a specific injury e.g. osteochondrosis, fracture, septic arthritis, foot abscess

Question 4

Answer 4

Acquired coffin joint contracture
* Seen in foals 1-4 months old; metacarpal bones are growing rapidly and there is functional shortening of the DDFT
* Stage 1: dorsal hoof wall has not passed vertical = good prognosis
* Stage 2: dorsal hoof wall has passed vertical = guarded prognosis

Question 5

How can we medically manage acquired coffin joint contracture and which stage of the disease is this suitable for?

Answer 5

Medical management suitable for Stage 1 only.
* Toe extensions and heel reduction to stretch the DDFT musculotendinous unit during weight bearing
* NSAIDs and omeprazole
* Reduce foal’s growth rate by reducing nutrition -> reduce feed to foal and mare/ early weaning
* Address other causes of pain

Question 6

How can we surgically manage acquired coffin joint contracture?

Answer 6

Question 7

Answer 7

Acquired fetlock joint contracture
* Horses 10-18 months old
* The radius/ tibia is growing and there is functional shortening of the SDFT and suspensory ligament
* Stage 1: fetlock remains behind vertical
* Stage 2: fetlock positioned in front of vertical, but can move behind vertical in weight bearing
* Stage 3: fetlock is positioning behind vertical always

Question 8

How can we medically manage acquired fetlock joint contracture?

Answer 8

• Toe extensions
• NSAIDs and omeprazole
• Reduce foal growth rate by reducing nutrition
• Splint to force the fetlock into extension
• Address other causes of pain
• This is suitable for Stage 1 only

Question 9

Surgical management of acquired fetlock joint contracture? Prognosis?

Answer 9

• Careful palpation of limb under GA when in full extension -> determine which structure causing contracture
• Procedure depends on structures involved and severity

Options (these are performed in additional to medical therapies)
* Desmotomy of accesory (check) ligament to SDFT
* SDFT desmotomy (guarded prognosis for athletic use)
* Desmotomy of accessory ligament to DDFT
* DDFT desmotomy (guarded prognosis for athletic use)
* Suspensory ligament desmotomy (guarded prognosis for athletic use)